Slide-valve.



No. 636,394. Patented Nav. 7, |899. T. R. BAILEY.

SLIDE VALVE.

(Application led Apr. 2B, 1899.]

(No Model.)

TH: Norms paens co. Pnm'omwo.. wAsnms'roN, o. c.

o valve or yoke.

A UNITED STATES PATENT OEEICE.

THOMAS R. BAILEY, OF PITTSBURG, PENNSYLVANIA.

SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 636,394, dated November 7, 18989.

Appnmion nea April 2s, 1899.

ro companying drawings, which form a part of this specification.

My invention relates to an improved steam slide-valve adapted for use upon locomotives or stationary engines; and it consists in the certain details of construction and combination of parts, as will be fully described hereinafter.

In the accompanying drawings, Figure 1 is `a side elevation of my improved port-chamzo ber, having the double yoke or slide-valve removed therefrom, showing the location of the several ports. Fig. 2 is an end elevation of the same, having the covering of the steam-chest in position. Fig. 3 is a sec- 2 5 tional plan view taken upon the line X X of Fig. 1, showing the slide-valve and its operative mechanism. Fig. 4 is a cross-section of the same, Fig. 3, taken upon the line Y Y. Fig. 5 is a side elevation of the slide-valve or go yoke. Fig. 6 is a sectional plan view of the stationary port-chamber of my improved valve.

To construct a non-frictional slide-valve in` accordance with my invention, I form either integral with the cylinder l or of a separate casting a stationary port-chamber 2, having the three ports 4, 4', and 5, the two, 4 4', leading to opposite ends of the said cylinder and the other or middle port, 5, to the exhaust. This structure 2 is provided with a flange or 4o guide 3 for the purpose of confining and properly guiding a sliding yoke or valve 18, which is moved back and forward by a valverod 14, by eccentrics, or in any manner well known in the art.- This yoke or valve consists of two separate pieces, the one analogous with the other and held or confined about the said stationary portion 2 by means of a suitable number of bolts 15, passed transversely through the ends of the said sliding These two sections of the sliding valve 18 are connected the one with Serial No. 714,910. (No model.) f

the other by a tongue and groove 17 and are in close contact with the stationary portion 2. Each of these sections of the sliding valve 18 is provided with rectangular recesses 10, capable of spanning 'or covering one of the steam-ports 4 and the exhaust 5, as shown at Fig. 3 of the drawings, and by a short movement'in the direction of its length closing the saidsteam-port 4 and connecting the exhaust-port 5 with the steam-port 4 on the opposite end of the cylinder.

The connection between the one section of the sliding valve 18 with the other, as above mentioned, is formed by a tongue and groove and the one sectionl held separate the one from the other by means of strong spiral springs 12, surrounding the tribolts 15 and adapted to keep the tongue-and-groove connection slightly separated in order that the sliding valve may be adjusted slightly toward or away from the stationary portion 2, and thereby reduce any unnecessary friction upon the ports. It will be noticed that by this construction and arrangement of a steam-valve as the metal used in the seat or stationary portion 2 is in the same proportion as that of the movable or valve part 18 therefore the expansion and contraction of the two ports are equal, thus reducing any friction on the ports to the minimum.

The springs 12 are of a sufficient strength to overcome the pressure of the steam against the side walls of the sliding valve and not permit the saidvalve to bear with any undue pressure against the stationary portion 2 of the valve. This stationary portion con sists of three ports, two for steam and one for the exhaust, and each port is formed with an expanded or enlarged exhaust (which is best seen at Figs. 1, 3, and 6 of the drawings) to permit a free and uninterrupted passage of the steam either entering the cylinder or leaving the same. The tension of the springs 12 tends to separate the sliding valve 18, and the bolts 15 are used to keep the said sliding valve in close working contact, and any wear upon the ports may be taken up by the said bolts, as is obvious.

It is a recognized fact that about one-fourth to one-half of the steampressure of any e11- gine is wasted or lost upon the operation of ICO the valves governing the cylinder. This loss of power is due to friction of the ports, and bythe use of a valve constructed as described the friction is reduced to the minimum.

It is obvious that various modications maybe made in the mechanical construction of my improved slide-valve. Therefore I do not conne myself to the exact construction shown and described.

Having thus described my invention, I claim- A slide-valve for cylinders, consisting of a stationary portion 2, a flange or guide formed integral with lthe upper end thereof, suitable 

